SR5,Thanks very much for the detailed info.It seems to be very difficult to decide,or work out which is better,more so if you like trying different oils.I have for the last 20 years used semi synthetics in this car,but i am now thinking that the 10w40/15w40 mineral oils appear to be so good nowadays,and so cheap,that the sensible choice would be to just use one of these and be done with it.I am now also looking at the new Castrol GTX Ultraclean in 10w40 flavour,just to make the choice even more complicated.I think my main criteria in choosing an oil for this car would be something that is good at resisting fuel dilution,short trips,along with good cleaning and heat/shear resistance.